The ongoing beef between Cardi B and Nicki Minaj flared out of control as the US rappers were reportedly involved in an vicious altercation at a New York Fashion Week party on Friday.

Cardi B - real name Belcalis Almanzar - posted a lengthy message on Instagram following the alleged fracas at the Harpers Bazaar event but did not name her New York rival.

The 25-year-old said she had "let a lot of s*** slide" and referred to "sneak disses", but said that she would not allow the person she was upset with to "mention my child".

The Bodak Yellow rapper, who gave birth to daughter Kulture in July, claimed the person had been liking social media comments questioning her parenting skills.

Videos soon emerged on Twitter appearing to show the altercation, but it is unclear who was involved.

According to TMZ, the new mother lunged towards the 35-year-old, whose real name is Onika Maraj, but was held back by security. Later, she reportedly threw a shoe in the direction of her rival and her entourage.

But sources close to Cardi B told the website the artist was not looking for a fight and that she only wanted to address "lies" that were allegedly being spread.

On Instagram, Cardi B wrote: "Ive let a lot of s*** slide! I let you sneak diss me, I let you lie on me, I let you attempt to stop my bags, f*** up the way I eat! Youve threaten (sic) other artists in the industry, told them if they work with me youll stop f****** with them!!

"I let you talk big s*** about me!! I addressed you once in person, I addressed you a second time in person, and every time you copped the plea!! But when you mention my child, you choose to like comments about me as a mother, make comments about my abilities to take care of my daughter is when all bets are f****** off!!

"Ive worked to (sic) hard and come too far to let anybody f*** with my success!!!! B*****s talk all that s*** in they (sic) raps but in real life they (sic) p****!!"

The pair, who worked together on the song Motorsport with rap group Migos, are said to have had bad blood since 2017.